diff --git a/testing-only b/testing-only
index eeb9548..7edf7eb 100644
--- a/testing-only
+++ b/testing-only
@@ -1,3 +1,4 @@
+#!/bin/sh
 # This file is of no use except for testing purposes. It is meant to make the installer more user-friendly by hiding the output, adding colour etc.
 
 echo -e "\e[1;36m"Running apt-get update and apt-get dist-upgrade for you..."\e[0m"